Findings:

• FX
• f(x)
• Boris FX
• soft/fx and fog enhancing filter
• Dos Fx (user)
• FXS
• fx (user)
• GeForce FX
• Stunt Race FX
• Casio FX 115W
• f(x) (user)
• Ivan FXS (user)
• Dub Fx

If you Log in you could create a "f(x)=x" node. If you don't already have an account, you can register here.